I recently had the timing belt go on my AMK S3. I've now got it all back together but there seems to be a missfire, mostly at low revs seems to clear when at higher revs. I do have the engine light on. When I got it home I took the oil filler off and a fair amount of smoke escaped. Have I done something severely wrong here, timing out etc, or do you think it could be blocked breather pipes with the build up of smoke in the head cover? Coilpacks and plugs were fine before belt let go so I think it's unlikely to be them and much more likely to be related to the head being off.